Angioimmunoblastic T-Cell lymphoma: A critical analysis of clinical, morphologic and immunophenotypic features

Background: Angioimmunoblastic T-cell lymphoma (AITL), a subtype of peripheral T-cell lymphoma (PTCL), is characterized by unique clinical and biological features. Its diagnosis remains a challenge as clinical presentation as well as pathologic findings are frequently misleading. Material and Methods: We retrospectively analyzed the clinical, morphological and immunophenotypic spectrum of 17 cases of histologically proven AITL. Result: The mean age was 54 years and male to female ratio was 2.4. Common clinical features included generalized lymphadenopathy (60%), hepatomegaly (70%), splenomegaly (50%), anemia (80%) and polyclonal hypergammaglobulinemia (100%). Microscopically, three architectural patterns; pattern I (6%), pattern II (41%) and pattern III (53%) were observed. Bone marrow infiltration was seen in 60% cases and 30% cases revealed plasmacytosis. Absence of follicles, polymorphous infiltrate, extra-follicular follicular dendritic cell (FDC) proliferation, high endothelial venules (HEV) prominence and neoplastic T-cells were the diagnostic features of AITL. CD10 positivity (47%), clear cells in the background (59%) admixture with large size CD20+ B-immunoblasts (35%) and bone marrow plasmacytosis (50%) were common observations. Conclusion: Awareness of various morphological and immunophenotypic complexities of AITL and distinction from reactive adenopathies and other types of lymphomas that mimic AITL is underscored in this study.